terminology: spawn → pour/wisp for molecules (gt-9uy0)

Molecules use chemistry verbs, not spawn:
- pour = create persistent mol (liquid)
- wisp = create ephemeral wisp (vapor)
- spawn = polecats only (workers)

Changes:
- Delete chemistry-design-changes.md (migration doc)
- Remove migration tables from sling-design.md
- Update bond tables: Spawn → Pour/Wisp
- Rename spawnMoleculeFromProto → pourMoleculeFromProto
- Rename spawnMoleculeOnIssue → runMoleculeOnIssue
- Update templates: bd mol spawn → bd wisp
- Update prime.go: commands and messages
- Clean all docs and comments

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

mayor/rig/docs/propulsion-principle.md

@@ -133,8 +133,8 @@ bd list --status=in_progress --assignee=<self>
 # 3. If attached: resume from current step
 bd ready                    # Find next step to work on
 
-# 4. If not attached: wait for work or spawn new molecule
-# (Patrol agents bond a new patrol molecule)
+# 4. If not attached: wait for work or create new molecule
+# (Patrol agents create a new patrol wisp)
 # (Polecats wait for assignment)
 ```